The dynamic range of a display is a ratio between the smallest and the largest possible luminance that can be reproduced. Contemporary displays such as televisions and computer monitors support displaying content with a high dynamic range (HDR). Such displays have peak luminance significantly higher than displays supporting only standard dynamic range (SDR).
Traditional cathode ray tube (CRT) displays typically have a dynamic range of one to three hundred (1:300) and peak luminance of about one hundred (100) candela per meter square (cd/m2). A Liquid Crystal Display (LCD) backlit by an instant fluorescent light emitter typically has a peak luminance of around three hundred to five hundred (300-500) cd/m2 and a dynamic range of one to eight hundred (1:800). CRT displays and LCD displays are examples of SDR displays.
An LCD display backlit by a grid of independently modulated light emitting diodes (LEDs), is an example of an HDR display, and can reach peak luminance of four thousand (4000) cd/m2 and a dynamic range of one to twenty thousand (1:20000). A display using quantum dot technology, is another example of an HDR display, and can reach a peak luminance forty thousand (40000) cd/m2 and exceed a dynamic range of one to ten to power four (1:104).
The human visual system (HVS) is generally known to be able to perceive luminance from as low as ten to the power of minus six (10−6) cd/m2 to as high as ten to the power eight (108) cd/m2. However, at any given time the human visual system (HVS) is known to be limited to a dynamic range of one to one thousand (1:1000). The human visual system (HVS) performs dynamic adaptation to viewing conditions as the viewing conditions change. The adaptation performed by the human visual system (HVS) is not instant and typically can take up to five (5) minutes to fully adapt to brighter environment and up to thirty (30) minutes to fully adapt to a darker environment. If, during a playback of video data, the speed of display luminance variations exceeds the human visual system (HVS) adaptation speed, a viewer can experience degradation of viewing experience and visual discomfort.